Disconnection box for a robot system

ABSTRACT

A switch-off box for a robot system has a two-part housing and a coupling device resiliently mounted in the housing and connected to a torch body and a hose pack or to a torch handle connected with the hose pack, and having a supporting surface for punctual contact on the housing. There are contacting or switching elements connected to the coupling device. Two oppositely located openings are provided in the housing for connection of the coupling device to the torch body and for connection of the coupling device to the hose pack or the torch handle. The supporting surface is connected with the contacting or switching elements so that a respective contacting or switching element will be activated or deactivated by lifting of the supporting surface from the housing, and a signal will be transmitted from the contacting or switching element to an interfaced control device, or the robot system.

CROSS REFERENCE TO RELATED APPLICATIONS

Applicants claim priority under 35 U.S.C. §119 of Austrian ApplicationNo. 1524/2002 filed Oct. 8, 2002. Applicants also claim priority under35 U.S.C. §365 of PCT/AT2003/000300 filed Oct. 6, 2003. Theinternational application under PCT article 21(2) was not published inEnglish.

BACKGROUND OF THE INVENTION

1. Field of the Invention.

The invention relates to a switch-off box for a robot system, includinga coupling means resiliently mounted in a housing and designed to beconnected to a hose pack and a welding torch formed by a torch body and,optionally, a torch handle.

2. The Prior Art.

Collision protection detection means or switch-off boxes are known fromthe prior art, yet these are directly installed in robots, i.e., in arobot arm. Components are attached to those switch-off boxes integratedin the robots. This involves the disadvantage of such integratedswitch-off boxes having to take up the entire weight of the attachedcomponents and hence to be very rigidly designed, thus adverselyaffecting the switch-off behavior.

From U.S. Pat. No. 4,540,869 A, a welding torch for use in a weldingrobot comprising a collision protection means is known, which includes aresiliently mounted coupling element designed to be connected to a hosepack and a welding torch. This entails the drawback of a relativelycomplex construction, which also serves to allow radial movements of thewelding torch.

JP 7-178546 A likewise discloses a welding torch including a collisionprotection means, yet the connection of the hose pack is notillustrated. If the hose pack were to be fastened to the coupling means,the switch-off box would have to take up the very high weight of thecomponents attached to the same, thus adversely affecting the switch-offbehavior.

GB 1 224 180 A shows a device for controlling the movement of a tool,for instance a welding torch, in which a finder can be mounted to detectthe path of movement of the tool. On a robot arm connected with thefinder are arranged elements to detect a collision of the finder withthe tool and actuate the motors of the robot control accordingly. Again,the switch-off behavior is adversely affected because of the collisiondetection means being installed in the robot arm.

SUMMARY OF THE INVENTION

The object of the present invention, therefore, consists in providing anindependent switch-off box capable of being flexibly used at any desiredsite or position of the robot system. In addition, the switch-off box isto be configured in a manner as simple as possible and characterized byas quick and simple a response as possible.

The objects according to the invention are achieved in that the housingis comprised of two parts and the coupling means is designed forpunctual contact on the housing. This offers the advantage of theswitch-off box being directly arrangeable in the welding torch, i.e.,between the individual components of the welding torch. The switch-offbox may, thus, be positioned as close to the jeopardized region aspossible so as to readily detect already slight collisions. A furtheradvantage resides in that the hose pack and the torch handle,respectively, can be connected with the switch-off box such that thelatter will take up the weight of the components and the resilientlymounted coupling means of the switch-off box need only be dimensioned tofit the weight of the torch body. The punctual contact of the couplingmeans on the housing ensures the rapid response behavior of theswitch-off box, since, at the occurrence of a collision, such collisionwill be immediately detected by the opening of the punctual contact andthe respective control of the robot system will be enabled by theappropriate arrangement of contacting elements or switching elements.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be explained in more detail by way of theaccompanying drawings, which illustrate an exemplary embodiment of theswitch-off box.

In the drawings,

FIG. 1 is a schematic illustration of a welding apparatus or weldingdevice;

FIG. 2 is a schematic illustration of the arrangement of a switch-offbox on the welding torch between the torch body and the hose pack;

FIG. 3 is another illustration of the arrangement of a switch-off box onthe welding torch between the torch body and the torch handle;

FIG. 4 is a front view of the switch-off box without any componentsattached thereto;

FIG. 5 is a sectional illustration through the switch-off box alonglines V-V of FIG. 4;

FIG. 6 is a sectional illustration through the switch-off box alonglines VI-VI of FIG. 4;

FIG. 7 is a sectional illustration through the switch-off box alonglines VII-VII of FIG. 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 depicts a welding device 1 or welding apparatus for variousprocesses and methods such as, e.g., MIG/MAG welding or WIG/TIG weldingor electrode welding methods, double wire/tandem welding processes,plasma or soldering methods etc. It is, of course, possible to use thesolution according to the invention with a power source or weldingcurrent source.

The welding device 1 comprises an energy source 2 including a powerelement 3, a control device 4 and a switch member 5 associated with thepower element 3 and the control device 4, respectively. The switchmember 5, and the control device 4, are connected with a control valve 6arranged in a feed line 7 for a gas 8 and, in particular, a protectivegas such as, for instance, CO₂, helium, argon and the like, between agas reservoir 9 and a welding torch 10, or a burner, respectively.

In addition, a wire advance system 11 common to MIG/MAG welding can beactivated via the control device 4, with a filler metal or a weldingwire 13 being fed via a feed line 12 from a supply drum 14 into theregion of the torch 10. It is, of course, also possible to integrate thewire advance system 11 in the welding device 1 and, in particular, inthe basic housing, as is known from the prior art, rather than design itas an accessory unit as illustrated in FIG. 1.

It is also possible for the wire advance system 11 to supply the weldingwire 13, or filler metal, to the process site externally of the weldingtorch 10, to which end a non-consumable electrode is preferably arrangedin the welding torch 10, as is common with WIG/TIG welding.

The power required to build up an electric arc 15 and, in particular, anoperative electric arc, between the welding wire 13 and a workpiece 16is supplied from the power element 3 of the energy source 2 to thewelding torch 10 through a welding line 17, wherein the workpiece 16 tobe welded, which is comprised of several parts, is likewise connectedwith the welding device 1 and, in particular, the power source 2 via afurther welding line 18, thus enabling a power circuit for a process tobuild up over the electric arc 15, or the plasma jet formed.

To provide cooling of the welding torch 10, the welding torch 10 isconnectable to a fluid reservoir and, in particular, water reservoir 21via a cooling circuit 19 with a flow control 20 interposed, whereby thecooling circuit 19, particularly a fluid pump used for the fluidcontained in the fluid reservoir 21, is started as the welding torch 10is being put into operation, thus effecting cooling of the welding torch10.

The welding device 1 further comprises an input and/or output device 22,via which the different operating parameters, modes of operation orwelding programs of the welding device 1 can be adjusted and/or called.In doing so, the welding parameters, modes of operation or weldingprograms adjusted by the input and/or output device 22 are transmittedto the control device 4, which, in turn, will subsequently activate therespective components of the welding apparatus or welding device 1.

Furthermore, the welding torch 10 in the exemplary embodimentillustrated is connected with the welding device 1 or welding apparatusvia a hose pack 23. The individual lines leading from the welding device1 to the welding torch 10 are arranged within the hose pack 23. The hosepack 23 is connected with the welding torch 10 via a coupling device 24or central connection, whereas the individual lines within the hose pack23 are connected with the individual contacts of the welding apparatus 1via connection sockets or plug-in connections. In order to ensure theappropriate strain relief of the hose pack 23, the hose pack 23 isconnected with a housing 26 and, in particular, the basic housing of thewelding device 1 via a strain relief means 25. The coupling device 24may naturally also be used for the connection on the welding device 1.

Basically, it should be noted that not all of the afore-mentionedcomponents need be used or employed for the various welding methods orwelding devices 1 such as, for instance, WIG devices or MIG/MAG devicesor plasma devices.

In FIGS. 2 and 3, an application example of a switch-off box 27 for arobot system and, in particular, a welding apparatus is illustrated. Inthis case, the switch-off box 27 is directly arranged on the weldingtorch 10, namely between a torch body 28 and a hose pack 23 in FIG. 2,and between the torch body 28 and a torch handle 29 in FIG. 3, whichtorch handle, for instance, includes an integrated wire feed to whichthe hose pack 23 is connected. The welding torch 10 with the integratedswitch-off box 27 is fastened to a robot system (not illustrated) by theaid of a fastening means 30.

The use of the switch-off box 27 directly on the welding torch 10 offersthe advantage of the switch-off box 27 having to take up less weight,thus exhibiting an improved switch-off behavior in the event of acollision. Moreover, the independent switch-off box 27 ensures optimumadaptations to be made in the arrangement of the switch-off box 27,since the latter may be used at the most diverse points in the robotsystem. It is also feasible to use the switch-off box 27 in such amanner that no welding components are connected, but that it is, forinstance, used between the robot arm and the fastening means 30 for thewelding torch 10.

FIGS. 4 to 7 schematically illustrate the switch-off box 27 in detail,wherein a coupling means 34 is resiliently mounted in a housing 33comprised of two parts 31, 32. The coupling means 34 is designed for theconnection of the welding torch 10, particularly its components, and thehose pack 23, with a commercially available central connection orcoupling device from welding technology being realized on the couplingelement 34 to connect the hose pack 23 with the welding torch 10. Thefunction of the switch-off box 27 resides in performing a collisiondetection, whereby the switch-off box 27 is designed as a compactstructural unit and hence an independent component capable of beingappropriately positioned as a function of its field of use.

The switch-off box 27 is configured in a manner that the coupling means34 is resiliently mounted in the housing 33 comprised of two parts 31,32wherein the coupling means 34 projects out of the housing 33 through anopening 35, whereas the other end of the coupling means 34 may terminatein the interior of the housing 33. The torch body 28 may be fastened tothe projecting end of the coupling means 34. A cavity 36 is formed inthe interior of the housing 33. The coupling means 34 is preferablyinsulated relative to the housing 33, thus allowing electric energy and,in particular, welding current, to be transmitted via the coupling means34. To this end, an insulation ring 37 is arranged in the exemplaryembodiment illustrated. Channels 38 may be arranged within the couplingmeans 34, whereby the supplied media such as, for instance, coolingliquid, protective gas, etc. may be transferred from one side of thecoupling means 34 to its other side, thus safeguarding the function ofthe welding torch 10. Furthermore, the coupling means 34 comprises asupporting surface 39 for the punctual contact on the housing 33, whichsupporting surface in the exemplary embodiment shown is formed by anexternal ring 40 having an L-shaped cross section and fastened to theinsulation ring 37. Said external ring 40 having an L-shaped crosssection may be designed to extend circumferentially or to comprise onlysome sections. Thus, it is ensured, on the one hand, that the couplingmeans 34 will be secured against slipping out of the housing 33 and, onthe other hand, that a punctual contact will be provided in the housing33. It is, in fact, essential that the coupling means 34 contacts thehousing 33 only point-wisely so as to enable the point-wise lifting fromthe housing 33 in the event of a collision. The external ring 40 may, ofcourse, also be formed by the coupling means 34.

In order to ensure a punctual abutment or contact on the housing 33,projections 41 are arranged on the external ring 40 so as to ensurepunctual bearing on the housing 33. Instead of the projections 41, it isalso feasible to use other spacer elements such as, for instance,spheres, in order to provide a punctual contact between the supportingsurface 39 and the housing 33. In a preferred manner, three or fiveprojections 41 are arranged there. The fixation of the coupling means 34is realized by the aid of a screw connection 42 through the externalring 40 and the supporting surface 39, respectively, with a springelement 44 arranged between a screw head 43 and the external ring 40 andthe supporting surface 39, respectively. Thus, the entire coupling means34 is resiliently mounted so as to cause the suitable displacement ofthe coupling means 34 at a collision of the connected parts and, inparticular, the torch body 28 with a solid object. In order for this tobe detected, contacting elements or switching elements 48 are connectedwith the projections 41 and the supporting surface 39, respectively, ina manner that the contacting element will be activated or deactivated bythe lifting of a single projection 41 from the housing 33 and a signalwill, thus, be transmitted from the contacting element or switchingelement to an interfaced control device 4, or the robot system.

Furthermore, another opening 45 is provided in the housing 33 on theopposite side of the emergence of the coupling means 34 such that thelines supplied through the hose pack 23 may be conducted into thehousing 33 to the coupling means 34. In a preferred manner, a furtherprojection, or a thread 46, is arranged to connect an external hose ofthe hose pack 23 to the housing 33. This is to ensure that the weight ofthe hose pack 23 will not directly act on the coupling means 34, butwill be transmitted onto the housing 33 of the switch-off box 27. Thespring elements 44 for the mounting of the coupling means 34 may, thus,be designed to be weaker so as to considerably enhance the responsebehavior of the switch-off box 27.

In principle, is should also be noted that the switch-off box 27 servesto detect a collision with an object, of the torch body 28 fastened tothe switch-off box 27. This is effected by a displacement or movement ofthe coupling means 34 in the interior of the housing 33, thus causing aprojection 41 to be lifted and a signal to be delivered. In doing so, itis essential that the coupling means 34 is mounted in the housing 33 ina manner that a defined displacement and, in particular, lifting of thepunctual bearings within the housing 33, of the switch-off box 27 willbe ensured at the occurrence of a collision. It is, in fact, thusfeasible to effect the suitable detection of a movement of the couplingmeans 34 by simply arranging contacting elements or switching elements,which constitutes a substantial structural simplification.

1. A switch-off box for a robot system, comprising: a two-part housing;a coupling means resiliently mounted in the housing and insulatedrelative to the housing, and being connected to a torch body and a hosepack or a torch handle connected with the hose pack, and having asupporting surface for punctual contact on the housing, said supportingsurface being formed by an external ring having an L-shaped crosssection, said coupling means allowing transmission of electric energy,and said coupling means having channels for transferring supplied mediafrom one side of the coupling means to another; and contacting orswitching elements connected to the coupling means; wherein twooppositely located openings are provided in the housing for connectionof the coupling means to the torch body and for connection of thecoupling means to the hose pack or the torch handle, wherein aprojection or thread is arranged on one side of the housing forconnection with an external hose of the hose pack, and wherein severalprojections are arranged on the external ring and on the supportingsurface, respectively, for punctual contact on the housing, saidprojections being connected with the contacting or switching elements sothat a respective contacting or switching element is activated ordeactivated by lifting of the supporting surface from the housing, and asignal is transmitted from the contacting or switching element to aninterfaced control device, or the robot system.
 2. A switch-off boxaccording to claim 1, wherein the housing is arranged between the torchbody and the hose pack.
 3. A switch-off box according to claim 1,wherein the housing is arranged between the torch body and the torchhandle, to which the hose pack is connected.
 4. A switch-off boxaccording to claim 1 wherein the coupling means projects out of thehousing through an opening, whereas the other end of the coupling meansterminates in the interior of the housing.
 5. A switch-off box accordingto claim 1, wherein the supporting surface is directly formed on thecoupling means.
 6. A switch-off box according to claim 1, whereinfixation of the coupling means is realized by a screw connection throughthe external ring and the supporting surface, respectively, with aspring element arranged between a screw head and the external ring andthe supporting surface, respectively.